import React, { Component } from 'react'

import {nanoid} from 'nanoid'
import './index.css'
import PropTypes from 'prop-types'

export default class Header extends Component {

    // 对接收的props进行：类型，必要性的限制
    static propTypes = {
      addTodo: PropTypes.func.isRequired,
    }

    handleKeyUp = (event) => {
      const {keyCode, target} = event
      if (keyCode !== 13) return 
      if (target.value.trim() === '') {
        alert('输入不能为空')
        return  
      }
      const todoObj = {id: nanoid(), name: target.value, done:false}
      this.props.addTodo(todoObj)
      target.value = '' 
    }

    render() {
        return (
          <div className="todo-header">
            <input onKeyUp={this.handleKeyUp} type="text" placeholder="请输入你的任务名称，按回车键确认" />
          </div>
        )
    }
}
